1. Field of the Invention
The present invention relates to a stay for a door mirror which is used for attaching the door mirror to a door panel of an automobile.
2. Description of the Related Art
As a stay for a door mirror of an automobile, conventionally, there have been known a one-piece type stay and a two-piece type one.
FIG. 1 is a schematic perspective view of such a one-piece type stay 10. The stay 10 has a triangular mount plate 11 which is fixed on a door panel of the automobile, and a mirror support 12 which is laterally projected from the mount plate 11 and supports a mirror unit 50 (FIG. 2). On the mirror support 12, there are provided a plurality of bosses 13 for fixing the mirror unit 50.
Ordinarily in this kind of one-piece stay, as shown in FIG. 2, a seal member 30 is fixed to a mount surface 11a, against the door panel, of the mount plate 11 by a double coated adhesive tape (double-sided adhesive tape). Further, a porous member 40 is fixed to the seal member 30 also by a double coated adhesive tape.
The seal member 30 is made of vinyl chloride (PVC), rubber and so on. The seal member 30 prevents a wind from blowing into the stay, or prevents a water from entering the stay. On the other hand, the porous member 40 can be elastically deformed to some extent, and is sandwiched between the stay and the door panel so as to further seal the inside of the stay with its elasticity.
The reason why the seal member 30 and the porous member 40, both are intended for sealing, are separately provided are as follows. It is necessary to surely seal the complicated configuration of the mount surface 11a of the mount plate 11, where the bosses for screwing and so on are provided. The following is also another reason. That is, the porous member 40 is generally formed by stamping from a sheet-like material, and therefore it can not effectively seal the complicated mount surface 11a.
In the above conventional constitution, two members of the seal member 30 and the porous member 40 must be fixed to one stay. Further, the seal member 30 and the porous member 40 are fixed with the double coated adhesive tape. Thus, the many parts are necessary, and therefore its assembling steps are increased in number. As a result, the manufacturing cost goes up.
FIG. 3 is a schematic perspective view of the abovementioned two-piece type stay 20. The stay 20 comprises a base 20a made of metal which provides necessary strength for the stay, and a base cover 20b made of resin which covers the base 20a from outside. The base 20a is provided with a projecting portion 22 which is laterally projected from a base plate 21. On the other hand, the base cover 20b is provided with a projecting portion 26 which is laterally projected from a triangular base plate 25. An opening 27 is formed at a region where the base plate 25 and the projecting portion 26 are connected with each other.
The projecting portion 22 of the base 20a is passed through the opening 27 so that the base 20a and the base cover 20b are connected with each other. Thus, the stay 20, which is similar to the stay 10 in FIG. 1, is assembled. The base plates 21 and 25 are integrated so as to form a portion corresponding to the mount plate 11 of the stay 10 in FIG. 1. The projecting portions 22 and 26 are integrated so as to form a portion corresponding to the mirror support 12 of the stay 10. On the projecting portions 22 of the base 20a, there are provided a plurality of bosses 23 for fixing the mirror unit.
Also in the two-piece type stay 20, like in the case of the one-piece type stay, there arises a problem of higher manufacturing cost due to using two members of the seal member and the porous member. Further, in the two-piece type stay, a wind-causing noise problem (i.e. occurrence of whistler, or of whistling sound) additionally arises, which will be explained below with reference to FIG. 4. FIG. 4 is a schematic sectional view taken along a 4--4 line in Fig, 3, wherein the stay is attached to the door panel of the automobile.
In FIG. 4, the mirror unit is not shown. A door panel 51, shown with an imaginary line, is one located at the most indoor side. Actually, other door panels also exist at outdoor side (stay side), and the constitution is complicated. Between the door panels and the seal member 30, a compressed porous member is sandwiched so as to perform sealing therebetween (in FIG. 4, the compressed porous member is not shown). Further, another decorative panel (not shown) is attached at the indoor side of the door panel 51.
In the two-piece type stay, air flows through a gap between two pieces. That is, air flows in from the gaps shown in FIG. 4 (arrows A and B), and this air flow leaks into the automobile thorough an opening 31 formed on the seal member 30 (see an arrow C), causing uncomfortable wind noise to the driver. The opening 31 is formed at a location corresponding to a female tapped hole 21a which is formed on the base plate 21 and receives a screw (not shown) used for fixing the stay to the door panel. Although, in FIG. 4, for the sake of clear explanation, the gaps between the stay and the seal member 30 are largely shown for overstatement, actual gaps are more narrow. But, the air flow enters the automobile through such narrow gaps under its wind pressure.